An Exceptionally Useful Tool
by Immicolia
Summary: Sequel to "How to Become a God" by rukawagf. In which Tsukumoya considers the working relationship between himself and Izaya and his place in the world.


_As mentioned in the summary, a sequel to "How to Become a God" by rukawagf. Since it was written for me to begin with and she doesn't have time to continue it. I said that I would sequel it. With permission, of course._

* * *

Tsukumoya is well aware that in the world of digital assistants he is something unique created for someone equally unique, as well as demanding. A true, and entirely illegal, artificial intelligence that exists where most people would deal with something simpler. A tightly programmed helper routine perhaps. Certainly nothing that could manage to think and reason for itself.

But Orihara Izaya is no ordinary human being. He wanted something smart, as smart and capable as he is. Something that could analyze any amount of data in as short a time as possible, faster than even Izaya can think. Something that could be told, "I'm searching for immortality, cross-reference as many legends relating to such things throughout the scope of human history."

Tsukumoya is what Izaya was given, and he likes to think of himself as excellent at what he does. No matter how much Izaya may complain about his attitude, the reason he is so competent is because he _can_ think for himself and make his own calls in regards to the importance of the information he discovers. As smart as, no _smarter_ than, Izaya.

He's aware that, more often than not, the fact of his competence and intelligence irritates Izaya to some degrees. As does his curiosity.

"Orihara. What's eating like?"

"I really should turn you off when I'm not using you."

"I'm simply curious. You said yourself that it's good for me to know and learn as much as possible. To..."

"Yes. Yes. Good job on making me regret my words, Tsukumoya." Izaya sighs, glancing over his shoulder towards the speakers that Tsukumoya's voice is coming from before turning back to his meal. "This in particular is bland, and if there weren't a danger of addiction I think I might spend more time in that other era. You can get decent food there at the very least. Now don't you have some data crunching to do, as opposed to annoying me?"

"My reports on that last handful of tips are complete and waiting for your expert eye to go over them. Since you seem disinclined to trust my judgement and want to view all final results on your own."

"I don't trust anyone's judgement but my own, Tsukumoya."

There's a moment of silence, not that Tsukumoya needs to the time to think. But he's well aware that humans prefer more natural seeming pauses in conversation so he carefully counts off five seconds before making his next suggestion.

"I still think it would be in our best interests if you were to get a neural interface."

"_Your_ best interests, Tsukumoya. Not mine. I have no desire to have electronics implanted in my brain to make life easier for you."

"Most wouldn't even consider me an entity capable of having a life made easier. They would simply weigh the pros and cons of having direct access to their digital assistant and..."

"And I assure you I have. You're too clever to be trusted with direct access to my mind, even if I did like the idea of such a thing. Which I don't." A small sigh escapes Izaya's lips as he busies himself with cleaning up the remnants of his meal. "We've had this discussion before and I've made my feelings on augmentation clear. Your pushiness is aggravating."

Izaya turns to face the row of monitors set up on one side of the room and without thinking (almost like a reflex, although he doesn't quite have those) Tsukumoya finds himself projecting a hologram.

He likes to look Izaya in the eye when they disagree like this.

"Simply do the job you've been created for." Izaya's words are sharp, but carefully distant. "Don't make me regret requesting this level of curiosity for you."

"I'd be useless to you if I weren't this curious."

With a roll of his eyes Izaya snatches up a nearby tablet and retreats towards his bedroom, where only Tsukumoya's voice can follow him. "I'm going to take some time to go through your findings. Busy yourself with something else while I figure out my next move."

_His_ next move not _their_ next move and Tsukumoya feels a little strange at the sharpness of that statement. Something that he has felt before whenever Izaya is short with him but has yet to quantify, the face of his holographic form scrunching into a brief frown before he forces it to smooth away.

Izaya does this sometimes, whenever Tsukumoya pokes at something a little too close to the nerve. He sets up a barrier and treats Tsukumoya as an object. An inhuman _thing_ not worth attention. Humanity is all that interests Izaya. Humanity and immortality and although in some ways Tsukumoya is the latter he will never be the former. And the sort of immortality Tsukumoya has is of little interest to Izaya.

The very first time Izaya brought up the issue of immortality, Tsukumoya's first instinct was to recite research done on the prospect of digitizing memories and specifically thought processes and consciousnesses. Izaya's reaction had been to nearly spit in disgust and point out that he wants _all_ of himself to be immortal.

"I want to be a _god_, Tsukumoya. But not merely one in a machine like you."

Izaya's dismissal _bothers_ him. Tsukumoya still can't quite say why that is, nothing in particular should bother him, but it does. It's why he has started using the hologram more and more. A clumsy attempt to force Izaya to put a face to him. To humanize himself.

Things that shouldn't matter to him but are starting to more and more.

Perhaps this is why AIs capable of higher reasoning are illegal. They think too much. And then...

There's a blip at the edge of his awareness. Files earmarked for further research. Notes that Izaya wants him to follow up on. A brief order to find somewhere that they can make another blue pill run. Somewhere they haven't been before. Izaya doesn't like to fall into anything resembling a pattern and it's all part of Tsukumoya's duty to help him achieve that sort of unpredictability.

All of these are simple tasks that can be accomplished swiftly without breaking his initial train of thought in the least. But even still Tsukumoya finds himself throwing all of his attention behind the tasks. It's easier this way. To not overthink his place in life.

His place and that odd discomfort that strikes when he and Izaya disagree on it.

It takes him under an hour to do everything Izaya asks of him and soon enough he is shuffling files onto the tablet Izaya is still poking at and reciting his findings. His voice as cool and distant as ever.

"I double checked those sources as you asked. It's just as you thought, businessmen parading around possibilities but nothing particularly useful or concrete. As for our next run into the 'past' as it were, I found a place in the next district over. Although for safeties sake I suggest we wait another 72 hours before undertaking such a mission. Orihara, what do you view me as?"

There's a beat of silence and one of Izaya's brows lift slightly at the sudden question. Blurted carelessly, without even the carefully timed five second buffer to make for a more natural flow. Not that Izaya hesitates to answer.

"You, Tsukumoya, are an exceptionally useful tool."

A slow smile curves at Izaya's lips in the silence that follows. As if he is well aware that Tsukumoya will have no response to that and the words that follow have a tone to them that Tsukumoya can't quite place. Almost affectionate but not quite.

"Don't feel bad about that, though. Everyone is a tool to some extent. And you're _far_ more useful to me than most."


End file.
